1. Field of the Invention
The present invention relates to a guiding module for rolling-element, and more particularly to a device for retaining rolling-element applied to linear transportation unit, the linear transportation unit is applied to machinery equipments, electronics, and automatic or semi conduction instruments.
2. Description of the Prior Arts
Conventional rolling-element retaining devices applied to linear transportation unit are generally divided into two categories: first one is an independent component rolling-element retaining device, and another one is a rolling-element retaining device made up of plural independent components. As shown in FIG. 7, wherein the slide block 60 is mounted onto a rail (not shown) and slides thereon, which is interiorly provided with a plurality of rolling elements 70 and between every two neighboring rolling elements 70 is inserted with a single partition 50 so as to prevent the rolling elements 70 from striking with each other. It is time-consuming to assemble this linear transportation unit by alternatively inserting the rolling element 70 and single partition 50 in the slide block 60. Furthermore, the partitions 50 and the rolling elements 70 should contact with each other properly, if the intervals between the rolling elements 70 and the partitions 50 are too big, the partitions 50 may be disengaged from the adjoining rolling elements 70 and it will collide the sidewall of the reflow passage when moving in the reflow path, and even worse that the reflow path may be jammed. On the other hand, if the distance between the rolling elements 70 and the partitions 50 is too tight, the rolling elements 70 are unable to smoothly move due to frictions produced between the rolling elements 70 and the partitions 50.
With reference to FIG. 8, which shows a rolling-element retaining device made up of plural independent components, wherein the rolling-element retaining device 51 is made up of plural independent partitions 511 linked together by a flexible link-ring 512, so as to confine the respective rolling elements 70 in the intervals between the neighboring partitions 511. The method of making this kind of rolling-element retaining device 51 is by putting the rolling elements 70 in a mould, and then made by plastic ejection moulding, the plastic material and the ejection moulding machine should be high quality, so the production cost is relatively increased. Furthermore, due to the special manufacturing method, the rolling-element retaining devices and the rolling elements are coupled with each other too closely, such that the rolling resistance of the respective rolling elements will be very big. Furthermore, the partitions are fixedly connected to the link-ring, the partitions are unable to rotate relative to the chain, such that this kind of rolling-element retaining device cannot smoothly move in a reflow path.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional guiding module for rolling-element.